Nowadays, the energy security as well as the environmental concerns has
made great attempts to find economically and environmentally friendly energy resources.
Biogas production via anaerobic digestion has been shown as a sustainable,
renewable and carbon neutral energy source which can reduce the global fossil fuels
dependency. Agricultural activities generate huge amounts of organic residues annually
worldwide. These are including crop residues, straw, stalks, branches, leaves,
waste from pruning, bagasse, residue from cotton ginning, oil cakes and animal manure.
Traditional methods such as burning of these residues cause adverse effects on
the environment such as greenhouse gas emission and pollution of air and water,
while they could be sufficiently converted into valuable products through anaerobic
digestion process. In order to enhance the efficiency of anaerobic digestion of the agricultural residues,
a sufficient pretreatment may be necessary to make the feedstock ready for microbial decomposition.
Besides, the optimization of microbial activity of anaerobic digestion via manipulation and
control of operational parameters is necessary and important. This paper presents a comprehensive review
on the latest studies investigating the potential of agricultural wastes as feedstock for biogas. The
review includes the investigations on the biomethane potential of agricultural residues as well as the
investigated pretreatments and operational conditions for the improvement of anaerobic digestion of